Building siding units

ABSTRACT

A siding unit for a building having an outer panel and a backing board. The outer panel includes an upper marginal portion having a generally horizontal web which extends rearwardly from the face portion of the panel and which terminates in an upturned generally vertical lip. The outer panel also includes a retainer part which extends along the upper marginal portion thereof. The retainer part extends below the web of the upper marginal portion. The outer panel includes a lower marginal or butt portion which interlocks with the panel retainer part of the siding unit in the lower adjacent siding course. The backing board of the siding unit includes upper and lower margins and has its lower margin positioned adjacent to the upper margin of a backing board in a lower adjacent siding course. The upper marginal portion of the outer panel of the siding unit is positioned and retained between the upper marginal portion of its backing board and the lower marginal portion of the backing board in the upper adjacent course. Securement means are driven through the backing board adjacent its lower marginal portion and into the building structure. The face portion of the outer panel of the siding unit is spaced sufficiently from its backing board at one or more locations so as to define air spaces between the outer panel and its backing board.

United States Patent 1 Nov. 28, 1972 Mattes [54] BUILDING SIDING UNITS[72] Inventor: Lee H. Mattes, South Bend, Ind.

[73] Assignee: Mastic Corporation, South Bend,

Ind.

[22] Filed: May 28, 1971 [21] Appl. No.: 148,015

Related US. Application Data [63] Continuation-in-part of Ser. No.7,123, Jan. 30,

1970, abandoned.

[52] US. Cl. ..52/521, 52/409, 52/531, 52/558 [51] Int. Cl. ..E04b 2/08,E04c 2/46, E04d 3/362 [58] Field of Search ..52/520, 521, 530, 531, 409,52/556, 542, 555, 558

[56] References Cited UNITED STATES PATENTS 2,231,006 2/ 1941Harshberger ..52/409 X 2,264,546 12/1941 Ochs ..52/521 2,328,977 9/1943Hasenburger et a1 ..52/520 2,626,577 1/1953 Roush et al. ..52/531 X2,961,804 11/1960 Beckman ..52/556 3,114,218 12/1963 Macquere ..52/531 X3,246,436 4/1966 Roush ..52/531 X 3,417,531 12/1968 Jones ..52/555 X3,468,086 9/1969 Warner ..52/540 3,485,004 12/1969 Mattes ..52/531 XPrimary Examiner-Alfred C. Perham Attomey0ltsch & Knoblock ABSTRACT Asiding unit for a building having an outer panel and a backing board.The outer panel includes an upper marginal portion having a generallyhorizontal web which extends rearwardly from the face portion of thepanel and which terminates in an upturned generally vertical lip. Theouter panel also includes a retainer part which extends along the uppermarginal portion thereof. The retainer part extends below the web of theupper marginal portion. The outer panel includes a lower marginal orbutt portion which interlocks with the panel retainer part of the sidingunit in the lower adjacent siding course. The backing board of thesiding unit includes upper and lower margins and has its lower marginpositioned adjacent to the upper margin of a backing board in a loweradjacent siding course. The upper marginal portion of the outer panel ofthe siding unit is positioned and retained between the upper marginalportion of its backing board and the lower marginal portion of thebacking board in the upper adjacent course. Securement means are driventhrough the backing board adjacent its lower marginal portion and intothe building structure.

' 7 Claims, 4 Drawing Figures SHEEIIUFZ /y////////ZZ z f 1 w W 9 I M 6 44 w w M 5 H2 u m A m I Y 4/ /////////7///////% INVENTOR. LEE H. MATTESATTORNEYS 4f A TTORNEYS PATENTEDHnv 28 I972 SHEEI 2 BF 2 BUILDING smmcUNITS CROSS REFERENCE TO RELATED APPLICATION This application is acontinuation-in-part of my U. S. application Ser. No. 7,123, filed Jan.30, 1970 now abandoned.

SUMMARY OF THE INVENTION This invention relates to a siding unit for abuilding or similar structure and specifically concerns a means forattaching a plurality of siding units, each comprising an outer paneland a backing board, to a frame structure.

The siding unit of this invention represents an improvement to thesiding unit forrnin g the subject matter of my US. Pat. No. 3,485,004,granted Dec. 23, 1969. The upper marginal portion of the outer panel ofthe unit includes a generally horizontal web which extends rearwardly ofthe face portion of the unit and which terminates at the rear edgethereof in an upturned generally vertical lip. A retainer part extendsbelow the web of the upper marginal portion and forms means forinterlocking with the lower marginal or butt portion of the outer panelof the siding unit in the upper adjacent siding course. Thebacking'board of the siding unit is positioned at the back face of theouter panel and includes upper and lower marginal portions. The lowermarginal portion of the backing board cooperates with the upper marginof the backing board in the lower adjacent siding course. The verticallip at the upper margin of the outer panel of the siding unit ispositioned and retained between the upper marginal portion of itsbacking board and the lower marginal portion of the backing board in theupper adjacent siding unit course. The outer panel is retained inposition by securement means, such as a nail, driven through the lowermarginal portion of the backing board in the upper adjacent sidingcourse and into the underlying frame structure.

In the siding units of this invention, the outer panels are not nailedto the building, but instead are hung on their respective backing boardswhich are nailed at their lower margins to the building structure. Eachbacking board cooperates with the backing board in the lower adjacentcourse and thereby serves to hold the outer panel of the siding unitinthe lower adjacent course against its backing board. The interlockedouter panels of adjacent siding units, by not being directly nailed orsimilarly secured to the building, are free to expand or contract duringuse. To reduce the tendency for the outer panels of the siding units towarp during use, the face portion of each outer panel is spaced from itsbacking board at one or more locations so as to define air spacesbetween the panel and board. These air spaces reduce the temperaturedifferential between the exposed front face and the rear face of theouter panel.

The face portion of each siding unit outer panel may include two or moregenerally parallel offset face parts. The upper of the face parts has alower edge which extends forwardly of the upper edge of the adjacentlower panel face and which is connected thereto by an integral web. Theupper edges of the panel face parts preferably lie in a generallyvertical plane and contact the panels backing board, thereby reducingany tendency for the siding unit to vibrate in the wind and createundesirable noise effects.

Accordingly, it is an object of this invention to provide siding unitsfor a building or similar structure in which each siding unit has abacking board which is secured to the building and which serves toposition and hold parts of the siding unit in the lower adjacent sidingcourse against the building.

It is another object of this invention to provide building siding unitseach having an outer panel and a backing board which serves to retainthe outer panel of the siding unit of the lower adjacent course inposition and which is spaced from the exposed face portion of its outerpanel.

It is a further object of this invention to provide a building sidingunit which is of economical construction and which can be rapidlyattached to a building or similar structure.

Another object of this invention is to provide a building siding unithaving a panel which is attachable to a building structure and which isengageable therewith at a plurality of points along its face portion soas to reduce any tendency of the panel to vibrate when subjected to windor similar climatic conditions.

Further objects of this invention will become apparent upon a reading ofthe inventions description.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a fragmentary perspective viewof one embodiment of the siding unit shown attached to a buildingstructure.

FIG. 2is an enlarged detailed sectional view taken along line 22 of FIG.1.

FIG. 3 is a fragmentary perspective view of another embodiment of thesiding unit shown attached to a building structure.

FIG. 4 is an enlarged detailed sectional view taken along line 4-4 ofFIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodimentsillustrated are not intended to be exhaustive or to limit the inventionto the precise forms disclosed. They are chosen and described in orderto best explain the principles of the invention and its application andpractical use to thereby enable others skilled in the art to bestutilize the invention.

Each siding unit shown in FIGS. 1 and 2 comprises an outer panel 10 anda backing board 12. Outer panel 10 of the siding unit may be formed fromflat plastic, such as polyvinyl sheeting or aluminum sheet blanks, whichare shaped by a series of progressive bending or forming dies. Outerpanel 10 includes an upper marginal portion 14, a face portion 16depending from marginal portion 14, and a butt portion 18 extending fromthe lower margin 22 of face portion 16.

Face portion 16 of outer panel 10 has an upper margin 20 which parallelsits lower margin 22. Face portion 16 includes an integral retainer part24 which extends along upper margin or edge 20 thereof. Retainer part 24preferably comprises a downturned forwardly projecting double-foldextension having an outer run 26 and a spaced inner run 28. Inner run 28of retainer part 24 defines, in cooperation with the remainder of theface portion 16, an inverted channel 32. Channel 32 has a narrowrestricted lower opening 34.

Upper marginal portion 14 of outer panel 10 includes a substantiallyhorizontal web 35 which extends rearwardly from the upper edge of outerrun 26 of retainer part 24 and which terminates in an upturnedsubstantially vertical lip 36 located rearwardly of face portion 16.

Butt portion 18 of outer panel includes a web 40 which extendsrearwardly from lower margin 22 of the face portion and which terminatesin an upturned, preferably forwardly inclined lip 42. Lip 42 of the buttportion 18 is adapted to be inserted upwardly into a narrow opening 34of the retainer part channel 32 of a siding unit in a lower adjacentsiding course.

Face portion 16 of outer. panel 10 may be of a smooth slightlyconcavo-convex configuration, or the fold-like appearance illustrated inFIGS. 1 and 2 which simulates a plurality of smaller overlapping sidingunit panels. Fold-like face portion 16 includes two or more longitudinalpanel parts 44 which lie in generally parallel planes and which may haveslightly concavo-convex configurations. The lower edge 46 of each upperpanel part 44 extends forwardly of and preferably slightly below theupper edge 47 of the adjacent lower panel part 44 and is connectedthereto by a web 50. The upper edge 47 of each panel part 44 preferablylies in substantially the same plane as upper margin 20 of face portion16.

Backing board 12- is preferably formed of rigid material, such asinsulating fiberboard or honeycombed light weight plastic, and has anupper lipped or thin-walled marginal portion 54 and a substantiallyparallel lower lipped or thin-walled marginal portion 56. Upper marginalportion 54 of the backing board includes a side wall 58 which is set infrom front face 60 of the backing board and separated therefrom by ashoulder 62. Lower marginal portion 56 of the backing board includes aside wall 64 which is set in from rear face 66 of the board andseparated therefrom by a shoulder 68. Backing board 12 is positioned atthe back side of face portion 16 with its lower marginal portion 56overlapping in complemental cooperation the upper marginal portion 54 ofthe backing board 12 of the siding unit in the lower adjacent course.Vertical lip 36 of the upper marginal portion 14 of the siding unitpanel in the lower adjacent course is positioned between side walls 58and 64 of the lapped backing board marginal portions 54 and 56 and isretained therein by means of nails 52 or similar securement means whichare driven through the overlapping backing board adjacently above itslower marginal portion 56 and into the inner building siding 48.Shoulder 62 at the upper marginal portion 54 of the overlapped backingboard 12 extends to and preferably abuts the lower surface of web 35 ofits outer panel 10. Rear face 45 of each panel part 44 is spaced fromthe front face 60 of its backing board 12 so as to define one or moreair spaces 59 located between each outer panel 10 and backing board 12of a siding unit.

To attach each siding unit heretofore described to inner building siding48, a backing board 12 is first positioned against the building siding48 with its lower marginal portion 56 overlapping web 35 and lip 36 ofthe upper marginal portion 14 of the underlying outer panel and theupper marginal portion 54 of the underlying backing board in the loweradjacent siding course. With either the lower end of marginal portion 54of the overlapping backing board 12 abutting web 35 of the outer panelin the lower siding course, a shown in FIGS. 1 and 2, or shoulder 68 atthe lower marginal'portion 56 of the overlapping backing board abuttingthe upper end of marginal portion 54 of the backing board in the loweradjacent siding course, nails 52 are driven through the overlappingbacking board adjacently above its lower marginal portion 56 and intobuilding siding 48. Butt portion 18 of an outer panel 10 is thenpositioned against the outer panel of the siding unit in the loweradjacent siding course and slid upwardly causing its lip 42 to bereceived within channel 32 of retainer part'24 of the lower adjacentouter panel and interlocked therewith. The upper marginal portion 14 ofthe outer panel 10'is then swung inwardly until its web 35 is positionedover shoulder 62 of the upper marginal portion 54 of the adjacentbacking board 12. Outer panel 10 can now be released since it willremain positioned against the adjacent backing board 12. The heretoforedescribed assembly procedure is repeated for another siding unitbeginning with another backing board 12 being positioned againstbuilding siding 48 and having its lower marginal portion 56 overlappingthe upper marginal portion 54 of the backing board in the adjacent lowercourse.

As best illustrated in FIG. 2, it is to be noted that with outer panel10 positioned against-its'backing board 12, edge 47 and upper margin 20of the face portion of the panel contact outer surface 60 of the backingboard and add rigidity to the assembled siding unit. his to beunderstood that retainer part 24 of the outer panel 10 of the sidingunits need not be limited to the doublefold type illustrated, but caninstead consist of other inverted channel-defining means such as theclip-type retainer illustrated and described in my US. Pat. No.3,485,004. It is also to be understood thatthe multiplepart face portionof the outer panel of thisinvention would have application in otherforms and types of siding, including siding which is attached to abuilding structure without a backing board.

Each siding unit shown in FIGS. 3 and 4 comprises an outer panel and abacking board 72. Outer panel 70 can be formed of a plmtic material andextruded into shape. Backing board 72 can be formed of 'the samematerials as the backing board 12 of the aforedescribed embodiment shownin FIGS. 1 and 2 is formed of. Each outer panel 70 includes an uppermarginal portion 74, a face portion 76 depending from marginal portion74, and a butt portion 78 extending from the lower margin 80 of faceportion 76. Face portion 76 of outer panel 70 has an upper margin 82which parallels its lower margin 80 and includes an integral retainerpart 84 which extends along its upper margin 82. Retainer part 84preferably comprises a downtumed, forwardly projecting extension which,in cooperation with the remainder of the face portion, defines aninverted channel 88. Channel 88 has a narrow restricted lower opening90.

Upper marginal portion 74 of outer panel 70 in-- cludes a substantiallyhorizontal web 92 which extends rearwardly from the upper edge ofretainer part 84 and which terminates in an upturned, substantiallyvertical lip 94 located rearwardly of face portion 76. Butt portion 78of outer panel 70 includes a web 96 which extends rearwardly from thelower margin 80 of the face portion and which terminates in an upturned,

preferably forwardly inclined lip 98. Lip 98 of butt portion 78 isadapted to be inserted upwardly into retainer part channel 88 of asiding unit in the adjacent lower siding course.

Backing board 72 is positioned at the back of face portion 76 of itsouter panel 70 with its lower end face 100 abutting and resting upon web92 of the outer panel 70 of the siding unit in the lower adjacent sidingcourse. The lower marginal portion 101 of the backing board ispositioned forwardly of lip 94 of the outer panel 70 of the loweradjacent siding course and serves, when nails 103 or similar securementmeans are driven through the backing board adjacently above lip 94 ofthe outer panel and into building siding 104, to cause the lowermarginal portion 101 of the backing board to urge lip 94 of the. loweradjacent siding panel against the building siding. As best shown in FIG.4, each outer panel 70 is positioned against its backing board 72 byhaving its butt portion lip 98 inserted into channel 88 of the outerpanel in the lower adjacent siding course, and its upper marginalportion web 92 resting upon upper end face 106 of the backing board. Thethickness of each backing board 72 at its upper end face 106 ispreferably substantially equal to the distance between rear face 108 ofouter panel face portion 76 and rear face 1 of outer panel lip 94 at web92 so that with lip 94 contacting the outer surface of building siding104, as shown in FIG. 4, the upper marginal portion 107 of theunderlying backing board 72 will be positioned against the outer surfaceof the building siding.

The method of attaching the siding units shown in FIGS. 3 and 4 abovedescribed to building siding 104 is similar to the method described forattaching the building siding units shown in FIGS. 1 and 2. A backingboard 72 is first positioned against building siding 104 with its lowerend face 100 resting upon web 92 and its lower marginal portion 101positioned in front of lip 94 of the underlying outer panel 70 in thelower adjacent siding course. Nails 103 are driven through the backingboard adjacently above lip 94 of the underlying outer panel 70 in thelower adjacent siding course and into building siding 104, as shown inFIGS. 3 and 4, to anchor the underlying outer panel in position. Thebutt portion 78 of an unattached outer panel 70 is then positionedagainst the outer panel of the siding unit in the lower adjacent sidingcourse and slid upwardly causing its lip 98 to be received withinchannel 88 of the retainer part 84 of the lower adjacent outer panel andinterlocked therewith. The upper marginal portion 74 of the unattachedouter panel 70 is then swung inwardly until its web 92 is positionedover and rests upon upper end face 106 of its backing board 72. Theunattached outer panel 70 can now be released since it will remainpositioned against its backing board. Another backing board 72 is nowpositioned against building siding 104 with its lower end face 100resting upon web 92 of the last positioned outer panel 70. The assemblysequence is then repeated until all siding units are attached to thebuilding siding. As shown in FIGS. 3 and 4, rear face 108 of each outerpanel 70 is spaced outwardly from front face 112 of its backing board 72and defines, in cooperation with the backing board, an air space 1 14located between parts of the face portion of the outer panel and thebacking board.

The backing boards 12 and 72 of this invention are positioned ingenerally the same plane when attached to the building, thus allowingbutt portions 18 and 78 of outer panels 10 and of the siding units to beof reduced dimensions at webs 40 and 96, and thereby conserving materialand reducing the cost of the siding unit.

It is to be understood that the invention is not to be limited to thedetails herein given, but may be modified within the scope of theappended claims.

What I claim is:

l. A siding unit for a building or like structure comprising an outerpanel and a backing board, said outer panel including spaced uppermarginal and butt portions and a connecting face portion, said uppermarginal portion including a generally horizontal web extendingrearwardly of said face portion and terminating at the rear edge thereofin an upturned generally vertical lip, said face portion havingsubstantially parallel upper and lower margins and including a retainerpart extending along the upper margin thereof, said retainer partextending below the web of said upper marginal portion, said buttportion extending rearwardly from the lower margin of said face portionand including an upturned lip, said retainer part receiving in slidableinterlocking cooperation the upturned lip of the butt portion of a saidouter panel in the upper adjacent siding course, said backing boardpositioned at the back of the face portion of said first mentioned outerpanel and including upper and lower marginal portions, the lowermarginal portion of said backing board overlying the upper marginalportion of a said outer panel in the lower adjacent siding course withthe vertical lip of said lower adjacent siding course outer panel beinglocated to the rear of said backing board lower marginal portion, thehorizontal web of said first mentioned outer panel overlying the uppermarginal portion of said backing board and having its vertical liplocated to the rear of a said backing board in the upper adjacent sidingcourse, means adjacently above the vertical lip of said lower adjacentsiding course outer panel securing said first mentioned backing board tosaid building or like structure and causing the lower marginal portionof said first mentioned backing board to be urged against the verticallip of said lower adjacent siding course outer panel, the face portionof said first mentioned outer panel having parts spaced from said firstmentioned backing board and defining in conjunction with said firstmentioned backing board air space means extending substantially from theretainer portion to the butt portion of said first mentioned outerpanel.

2. The siding unit of claim 1 wherein said first mentioned backing boardhas a lower end face, said end face resting upon the horizontal web ofsaid lower adjacent siding course outer panel, said securing meansurging the lower marginal portion of said first mentioned backing boardagainst the vertical lip of said lower adjacent siding course outerpanel.

3. The siding unit of claim 2 wherein said first men- .tioned backingboard has an upper end face, the

horizontal web of said first mentioned outer panel resting upon saidupper end face, the thickness of the upper marginal portion of saidfirst mentioned backing board at its upper end face substantiallyequalling the distance between the face portion of said first mentionedouter panel at its horizontal web and the rear face of the vertical lipof said first mentioned outer panel.

4. The siding unit of claim 1 wherein the face portion of said firstmentioned outer panel includes front and rear faces, that portion ofsaid rear face extending from adjacent the retainer portion to the buttportion of said first mentioned outer panel being spaced from said firstmentioned backing board.

5. The siding unit of claim 1 wherein the upper and lower marginalportions of said first mentioned backing board are a thin-walledconstruction, said thin-walled upper marginal portion having a firstside wall set'in from the front face of said first mentioned backingboard and separated therefrom by a first shoulder, said thin-walledlower marginal portion having a second side wall set in from the backface of said first mentioned'backing board and separated therefrom by asecond shoulder, the horizontal web of said first mentioned outer paneloverlying and abutting said first board shoulder with the vertical lipof said first mentioned outer panel positioned adjacently forwardly ofsaid first board side wall, the thin-walled lower marginal portion ofsaid first mentioned backing board overlying the upper marginal portionof said lower adjacent siding course outer panel with said second boardside wall positioned adjacently forwardly of the vertical lip of saidlower adjacent siding course outer panel.

6. The siding unit of claim 5 wherein the thin-walled upper and lowermarginal portions of said first mentioned backing board are continuouswith the back and front faces respectively of the first mentionedbacking board, and the combined thickness of said thin-walled upper andlower marginal portions and the vertical lip of said first mentionedouter panel is substantially equal to the thickness of said firstmentioned backing board as measured between said front and back facesthereof.

7. The siding unit of claim 1 wherein the face portion of said firstmentioned outer panel includes at least two generally parallel ofl'setlongitudinally extending face parts, the lower edge of the upper one ofsaid face parts extending forwardly of the-upper edge of the loweradjacent face part and connected thereto by a web, the upper margin ofsaid first mentioned outer panel face portion and said lower face partupper edge contacting the front face of said first mentioned backingboard, each face part except for said contacting margin and edge beingspaced from said first mentioned backing board.

1. A siding unit for a building or like structure comprising an outerpanel and a backing board, said outer panel including spaced uppermarginal and butt portions and a connecting face portion, said uppermarginal portion including a generally horizontal web extendingrearwardly of said face portion and terminating at the rear edge thereofin an upturned generally vertical lip, said face portion havingsubstantially parallel upper and lower margins and including a retainerpart extending along the upper margin thereof, said retainer partextending below the web of said upper marginal portion, said buttportion extending rearwardly from the lower margin of said face portionand includIng an upturned lip, said retainer part receiving in slidableinterlocking cooperation the upturned lip of the butt portion of a saidouter panel in the upper adjacent siding course, said backing boardpositioned at the back of the face portion of said first mentioned outerpanel and including upper and lower marginal portions, the lowermarginal portion of said backing board overlying the upper marginalportion of a said outer panel in the lower adjacent siding course withthe vertical lip of said lower adjacent siding course outer panel beinglocated to the rear of said backing board lower marginal portion, thehorizontal web of said first mentioned outer panel overlying the uppermarginal portion of said backing board and having its vertical liplocated to the rear of a said backing board in the upper adjacent sidingcourse, means adjacently above the vertical lip of said lower adjacentsiding course outer panel securing said first mentioned backing board tosaid building or like structure and causing the lower marginal portionof said first mentioned backing board to be urged against the verticallip of said lower adjacent siding course outer panel, the face portionof said first mentioned outer panel having parts spaced from said firstmentioned backing board and defining in conjunction with said firstmentioned backing board air space means extending substantially from theretainer portion to the butt portion of said first mentioned outerpanel.
 2. The siding unit of claim 1 wherein said first mentionedbacking board has a lower end face, said end face resting upon thehorizontal web of said lower adjacent siding course outer panel, saidsecuring means urging the lower marginal portion of said first mentionedbacking board against the vertical lip of said lower adjacent sidingcourse outer panel.
 3. The siding unit of claim 2 wherein said firstmentioned backing board has an upper end face, the horizontal web ofsaid first mentioned outer panel resting upon said upper end face, thethickness of the upper marginal portion of said first mentioned backingboard at its upper end face substantially equalling the distance betweenthe face portion of said first mentioned outer panel at its horizontalweb and the rear face of the vertical lip of said first mentioned outerpanel.
 4. The siding unit of claim 1 wherein the face portion of saidfirst mentioned outer panel includes front and rear faces, that portionof said rear face extending from adjacent the retainer portion to thebutt portion of said first mentioned outer panel being spaced from saidfirst mentioned backing board.
 5. The siding unit of claim 1 wherein theupper and lower marginal portions of said first mentioned backing boardare a thin-walled construction, said thin-walled upper marginal portionhaving a first side wall set in from the front face of said firstmentioned backing board and separated therefrom by a first shoulder,said thin-walled lower marginal portion having a second side wall set infrom the back face of said first mentioned backing board and separatedtherefrom by a second shoulder, the horizontal web of said firstmentioned outer panel overlying and abutting said first board shoulderwith the vertical lip of said first mentioned outer panel positionedadjacently forwardly of said first board side wall, the thin-walledlower marginal portion of said first mentioned backing board overlyingthe upper marginal portion of said lower adjacent siding course outerpanel with said second board side wall positioned adjacently forwardlyof the vertical lip of said lower adjacent siding course outer panel. 6.The siding unit of claim 5 wherein the thin-walled upper and lowermarginal portions of said first mentioned backing board are continuouswith the back and front faces respectively of the first mentionedbacking board, and the combined thickness of said thin-walled upper andlower marginal portions and the vertical lip of said first mentionedouter panel is substantially equal to thE thickness of said firstmentioned backing board as measured between said front and back facesthereof.
 7. The siding unit of claim 1 wherein the face portion of saidfirst mentioned outer panel includes at least two generally paralleloffset longitudinally extending face parts, the lower edge of the upperone of said face parts extending forwardly of the upper edge of thelower adjacent face part and connected thereto by a web, the uppermargin of said first mentioned outer panel face portion and said lowerface part upper edge contacting the front face of said first mentionedbacking board, each face part except for said contacting margin and edgebeing spaced from said first mentioned backing board.